Heat-exchange device



Feb. 9 1926. 1,572,374

H. L. ALLAN HEAT EXCHANGE DEVICE Filed Dec. 15, 1919 2 hee l .Fi/yl. h

A? llllllll||| Feb. 9 1926.

H. L. ALLAN Filed Dec. 15, 1919 HEAT EXCHANGE DEVI CE 2 Sheets-Sheet 2Patented Feb. 9, 1926.

UNITED STATES fiUGH LOGIE ALLAN, or AYR, SCOTLAND.

H AT EXCHANGE nnvxcn.

Application filed December 15, 1919., Serial No. 344,791.

vTo all whom it may concern:

dom of Great Britain and Ireland, and resident of 46 Park Circus,'Ayr,Scotland, and of the- Btu-mall Oil Company Limited, Rangoon (Post BoxNo. 67), Burmah, British India, have invented a certain new and usefulHeat-Exchange Device, of which the following is a specification.

This invention relates to an improved heat exchange device for thecontinuous distillation and continuous fractionation of petroleum orother hydrocarbons or mixture of volatile liquids, and has for itsobject to improve the apparatus described. in the specification ofUnited States Patent No. 1,390,742 with a View to obtaining a largerproduction of light and heavy benzine of given density than thatobtained by'existing dephlegmation methods, and also to obtain themaximum yieldof white products continuously and in one operation.

According to the present invention the ap paratus comprises a series ofvessels for evaporating, distilling and fractionating hydrocarbons orthe hke, the vessels being I each divided into three superposed compartments, the oil being fed to the lowermost compartment and passing fromthence into the uppermost compartment through tubes in .the intermediatecompartment. Preferably the uppermost compartmentis provided with tubesin staggered relation to the tubes in the intermediate compartment andextending therefrom for a distance upwardly, so that the oil ascends thetubes and de scends outside the tubes in the uppermost compartment,flowing down the outer Walls of the tubes in the form of a film, beforepassing through a cascade pipe intothe lower compartment of the adjacentvessel.

During its passage through the vessels the oil is heated by vapourswhich pass through the intermediate compartments of the vessels. Thelighter ortions of the oil are thus evaporated o "and pass into afractionating apparatus.

.The fractionating apparatus preferably comprises two rows ofatmospheric fraction atmg condensers connected in cascade formation, theatmospheric condensers being substantially of similar construction tothe aforesaid vessels.

For the sake of convenience the invention will be hereinafter describedwith reference to the accompanying drawingswhereonz- Fig. 1 is adiagrammatic front View of the atmospheric condensers or fractionatingapparatus.

Fig. 2 is a fragmentary detail view of two adjacent atmosphericcondensers.

Fig. 3 is a vertical sectional view of the lower portion of one of theatmospheric condensers. I

As shown on F igs.- 1 and 2 of the accompanying drawings, the apparatuscomprises a plurality of atmospheric condensers A to A". I

As shown in Fig. 3 the atmospheric condensers are divided by partitionsinto three compartments 70, Z and mby means of a lower partition or tubeplate 7) and an upper partition composed of two tube plates 41. and 0,the tube plates supporting two series of tubes 1', s. The atmosphericcondensers are connected in cascade formation by means of cascade pipes16 connecting the compartment 7: of one vessel to the compartment mofthe adjacent vessel.

4 The li hter portions of crude oil evaporated off in a preheater passthrough the pipes 27 (Fig. 1) to the atmospheric condenser A Y Thecondensates in the atmospheric condensers cascade or flow backwardlyfrom one condenser to the next, and are thusre-evaps orate'd by thehigher temperature of the condensates in the atmospheric condensers towhich they return.

The units of the fractionating apparatus may be heated by steam or hotoil, the steam or hot oil being admitted to the intermediate compartmentZ of the units so as to pass around the tubes 8 therein (Fig. 3). If hotoil is used, it would be admitted by the connection 25 at the lower endof the compart-' ment 1 and be discharged'from the outlet 13 near theupper end thereof. The lowermost compartment m may also be heated bysteam through steam pipe 26. Preferably, two tube plates 01. and 0'spaced slightly apart are employed to separate the intermediatevcompartment Z from the uppermost com-' ment is by the upper plate n.Owing to the oil overflowing the upper tubes 1' and flowing down theouter walls thereof, maximum re-evaporationis facilitated, thus givingin- .creased efliciency.

If desired, the pipes of the atmospheric condensing apparatus may becooled by either air or water, but as water cooling has objections suchas liability to corrosion and excessive cooling, additional air-cooledsurface for the pipes may be provided by fitting them with internal airconduits, supplied with either natural or forced draught and fitted withcontrol valves for controlling the cooling effect. I

The atmospheric condensers are connected by the condenser pipes 27indicated diagrammatically in Fig. 1. Preferably the pipes 27 areconnected to headers 29 (Fig. 2% one header 29 connecting the risingpipes 2 of one condenser with the falling pipes 27 of the adjacentcondenser. The cascade pipes 16 may be provided with overflow pipes 30(Fig. 3) and valves 31 indicated diagrammatically in 2.

As will be seen, with particular reference to Fig. 3, the oil enters at16 and rises' through tubes .5- and 4,flowing down the outer surfacesofthe latter and escaping by the outlet pipe 16 which forms the inletfor the next lower condenser of the series.

30 The vapours escape at the top of (the conof the pipe arrangementdiagrammatically shown in Fig. 1 and more specifically in Figpartment tothe space between the tube plates, a second series of tubes extendingpartially into the uppermost compartment from the said space, a liquidoutlet .near the bottom of said uppermost compartment, :1.

vapour outlet in the 'top of the uppermost compartment and means forcirculating a heating-medium around the first-mentioned series of tubes.

2. A heat 'exchange device as specified in claim 1v having an externaloverflow pipe connecting the upper part of the uppermost compartmentwith the liquid outlet in the bottom thereof.

3. A heat exchange device as specified in claim 1 having condenser pi esextending upwardly from the vapour out et.

nUcn LOGIE ALLAN.

